.img_box
{
  margin-left: 26%;
}
.nav
{
    position: fixed;
    bottom: 50px;
    left: 500px;
    z-index: 999;
}
.nav .back
{
    position: relative;
    width: 45px;
    height: 45px;
    padding: 0;
    left: -80px;
    top: 40px;
}
.nav .nextZj
{
  position: relative;
  top: -50px;
  left: 180px;
  float: right;
  line-height: 45px;
  font-size: 15px;
}
.nav .nextZj button
{
  margin-left: 15px;
}
.popupClass
{
  height: 450px;
  padding: 5px;
}
.list_box
{
  padding: 10px 4px;
  box-sizing: border-box;
}
.span
{
  display: inline-block;
  width: 100%;
  padding: 5px 2px;
  box-sizing: border-box;
  text-align: center;
  line-height: 30px;
  font-size: 15px;
  color: #323233;
  background-color: #fff;
  border: 1px solid #ebedf0;
  border-radius: 5px;
}